1. Field of the Invention
The present invention relates to a logic diagram compiler/executor used for design of a logic system such as the actuation logic for engineered safeguard functions in a nuclear power plant and to the production of a logic diagram representation that can be executed using truth tables representing the different logic functions and, more particularly, the present invention includes a method of interactively creating a logic diagram representing actuation logic when the diagram is free from errors, creating a tabular representation of the logic diagram and executing the tabular representation to produce the desired outputs.
2. Description of the Related Art
In a nuclear power plant, engineered safeguard functions consist of actions to be taken to mitigate damage and ensure safety under abnormal or emergency conditions. These actions may be initiated manually, by means of pushbuttons or automatically, based on inputs from sensors which can transmit information concerning process variables and the states of actuated devices such as valves and pumps. To control the actuated devices necessary to implement the desired safeguard functions, the sensor inputs are processed by redundant logic networks which generate outputs through a power interface to energize or deenergize the proper devices in the proper sequences subject to any required enabling or interlock signals.
To design the logic for a nuclear power plant, a fluid systems engineer reduces the desired safeguard actions to a sequence of operations of various fluid control devices such as valves and pumps. The engineer then transposes the sequence of operations into the form of a logic or interlock sketch. The logic sketch is used by the engineer to develop a logic diagram and the necessary circuitry for the elementary wiring diagrams. The elementary wiring diagrams for a hardware circuit which is functionally equivalent to the logic diagram is created. The task of creating the logic diagram, subsequent wiring diagrams and the hard wired logic is very time-consuming and costly.